Influence of fertilizer and time of its application on growth, yield, and quality of pecans

The tree growth and nut yield and quality of the Moore pecan grown on Greenville sandy loam soil with fertilizer applied at different times are reported. Fertilizers were applied as follows: All in February; one-half in February and one-half in April; one-half in February and one-half in June; one-half in February and one-half in August; one-half in February and one-half in October; and 1/6 in January, February, April, June, August, and October. A plot with no fertilizer was included as a check. All treatments and the check included the same winter green manure crops and cultivation. Tree growth was increased by all fertilizer treatments, the largest average increase being from fertilizer applied in six light applications. Nut yields were significantly increased by all fertilizer treatments when compared to unfertilized trees. Time of fertilizer application had no significant influence on yield. There was an inverse correlation between the yield and the size of the nuts. The quality of the nuts, as measured in terms of specific gravity and percentage of well-filled nuts, was influenced by the time of the fertilizer application. The nuts of poorest quality were produced on the trees receiving one-half of the fertilizer in February and one-half in June; and those of best quality were produced on unfertilized trees. The oil and the protein content for the two "on-year" crops of 1937 and 1939 varied widely for the two seasons. There was less variation in these constituents due to fertilizer treatments, and no definite relationship with such treatments was evident. Fertilizer applied in split applications at different times during the season has not given significantly higher yields than when it was applied in a single application in February; and the quality of the nuts produced from this latter method compared favorably with the best quality produced with the former. Therefore, the one single application made in February might well be adopted on the basis of economy.